1. Technical Field
The present disclosure generally relates to the field of illumination devices and, more particularly, to multi-purpose illumination systems having visual alert capabilities.
2. Description of the Related Art
Approximately twenty million cloud-to-ground lighting strikes occur in the United States over the course of a year. According to the National Weather Service, between the years of 1999 and 2008, lighting caused an average of 62 deaths and over 300 injuries per year in the United States. Lightning annually causes upwards of 2,000 deaths worldwide. Since atmospheric electrical activity increases during warmer weather portions of the year when people are engaged in outdoor activities, the risk posed by such atmospheric electrical activity is quite high.
Lightning can occur with or without accompanying precipitation and can travel up to 25 miles from the point of origin to the point of contact with the earth, which places even persons outside of the thunderstorm or thundershower proper at risk. Adding to the risk, except in the moments immediately preceding a strike, lightning generally provides no physical warning or sensation to those present in the path of the strike. Thus dangerous and sometimes deadly lightning strikes do occur “out of the blue” without advance warning and at a distance of miles or even tens of miles from the nearest incidence of atmospheric electrical activity.
Many municipalities, industrial, and commercial entities operate exterior lighting networks that illuminate streets, intersections, highways, parking lots and businesses during evening hours and periods of reduced visibility. To provide the most effective and efficient illumination, the individual lights within these lighting networks are usually located in exposed, highly visible locations. Historically, such lights have used mercury vapor or metal halide lamps to provide illumination. While mercury vapor and metal halide lamps have proven more robust and longer-lived than incandescent bulbs, mercury vapor and metal halide lamps require a significant warming period prior to operation and are not designed for services where rapid changes in illumination or luminous output are desired. Newer, more energy efficient lighting technologies, for example solid state lighting systems, typically do not require an extended warming period prior to operation and are much more amenable to dimming and other rapid changes in illumination.
New approaches to improving public awareness of atmospheric electrical activity using existing infrastructure networks are therefore needed.